Apparatus for flocking cylindrical bodies

ABSTRACT

Plastic hair rollers are flocked on automatic machinery in which they are fastened to a conveyor for movement therewith and for rotation about their axes which are at right angles to the direction of conveyor movement. The rollers are dipped in a cleaning liquid in a first processing station, dried by evaporation of the liquid in a second, coated with adhesive composition in a third station, exposed to a stream of fibers moving in an electrostatic field at a fourth station, and the adhesive is cured at a fifth station, whereupon excess fibers are brushed off and the rollers are taken from the conveyor. They are rotated about their axes in most of the processing steps by rolling engagement of a supporting ball bearing on the conveyor with a drive belt or a stationary rail.

United States Patent 1 1 Schneck et al. [4 1 Apr. 3, 1973 [54] APPARATUS FOR FLOCKING 2,465,128 3/1949 Starkey ..117/93 CYLINDRICAL BODIES 2,698,814 1/1955 Ransburg ..118/638 3,498,817 3/1970 Stone ..117/33 [75] Inventors: Waldemar Schneck, Neckartenzhngen; Dieter Huitenlocher, Koengen, Primary Examiner-Mervin Stein both of Germany Assistant Examiner-Leo Millstein [73] Assignee: Walter Huttenlocher, Kongen-Ess- Attorney-Kama & Berman lin e ,Germ n 2 l g r 1 a y 57 ABSTRACT 2 F d: Feb. 3 971 1 Plastic hair rollers are flocked on automatic machin- [21] Appl. No.: 112,369 cry in which they are fastened to a conveyor for movement therewith and for rotation about their axes 52 us. 01. ..l18/630, 117/26, 118/640 are at 1* f .f [51] In Cl Bosh 5/02 movement. The rollers are dipped in a cleanmg l1qu1d in a first processing station, dried by evaporation of [58] new of Search 5 the liquid in a second, coated with adhesive composil tion in a third station, exposed to a stream of fibers moving in an electrostatic field at a fourth station, and [56] Reerences cued the adhesive is cured at a fifth station, whereupon ex- UNITED STATES PATENTS cess fibers are brushed off and the rollers are taken from the conveyor. They are rotated about their axes 2,806,803 9/1957 Thackara et a1 ..1 17/ 17 in most of the processing steps by rolling engagement 3,029,156 4/1962 Keene ..117/29 f a su porting ball bearing on the conveyor with a Melton et a1. drive belt o a stationary aiL 3,411,931 11/1968 Burnsetal. ..ll7/17 2,811,134 10/1957 Friderici ..118/636 3 Claims, 2 Drawing Figures D DDDDD uuuuuun uunuuug UDDDDDUDU PATENTEUAPRS 1975 APPARATUS FOR FLOCKING CYLINDRICAL BODIES This invention relates to apparatus for electrostatically flocking cyllindrically shaped bodies of fragile material in automatic operation.

In its more specific aspects, the invention will be described hereinafter in its application to the flocking of plastic hair rollers or curlers, but it will be understood that neither the specific material of construction nor the intended use of the generally cylindrical bodies is critical to the operation of the apparatus.

Flocked plastic hair rollers which are hollow plastic cylinders whose walls are perforated to form a screen or grid have only negligible heat conductivity and very low heat capacity. They do not become uncomfortably hot under the heat of a hair drier, and their flockcoated soft surfaces cannot damage tender hair as may occur with bare plastic or metal. The soft flock yields under the tension of the hair as the latter shrinks during drying. Air can pass freely through the large perforations, and the drying time is short. When heat-curing adhesives are employed, the rollers may be washed in water-in a simple manner.

It is an object of this invention to provide apparatus for flocking plastic hair rollers and like bodies of generally cylindrical shape made of fragile material which requires little labor and produces a uniform product of high quality.

In its more specific aspects, the invention resides in an improved device for attaching the substantially cylindrically shaped bodies that are to be flocked to a continuous elongated carrier in longitudinally spaced relationship for movement through a sequence of processing stations.

Other features, additional objects, and many of the attendant advantages of this invention will readily become apparent as the same becomes better understood by reference to the following detailed description of a preferred embodiment of automatic flocking apparatus when considered in connection with the appended drawing in which:

FIG. 1 shows a hair roller mounted on a processing conveyor of the invention, only a portion of the conveyor being shown in front elevation, and partly in section; and

FIG. 2 shows the entire conveyor and associated processing devices in side elevation on a scale much smaller than that of FIG. 1.

The hair roller 1 illustrated in FIG. 1 is a hollow cylinder of relatively heat resistant plastic, such as polyvinyl chloride, whose wall has large, rectangular perforations arranged in axial columns and circumferential rows. Circumferential ribs reinforce the axial ends of the roller and are engaged by spherical abutments 2,2, at the ends of respective shafts,3,3' coaxial with the roller 1 and are partly received in the bore of the roller 1. The shaft 3' has two telescoping portions biased axially apart by a helical compression spring 3 in the tubular shaft portion on which the abutment 2 is mounted, thereby permitting the abutment 2' to move between the fully drawn position and the position indicated in chain-dotted lines.

The ends of the shafts 3,3 remote from the abutments 2,2 are coaxially fastened to the cylindrical outer shells 4,4 of two ball bearings whose inner races are fixed on respective links of two chains 5,5 of a chain conveyor better seen in FIG. 2. Spring-loaded pairs of abutments 2,2 are longitudinally offset on the chain conveyor 5,5 to permit rollers 1 to be mounted on the conveyor in longitudinally spaced relationship with their axes perpendicular to the direction of conveyor movement.

Only the chain 5 is indicated by a chain-dotted line in to represent the conveyor which travels in a closed loop over multiple guide sprockets 5" from a loading station through several processing stations to an unloading station, and back to the loading station. A bin 6 at the latter holds uncoated plastic rollers l which are sequentially withdrawn by a belt conveyor 7. An operator at the loading station inserts the rollers 1 between abutments 2,2 passing the loading station on the conveyor 5, the conveyor being driven continuously by some of the guide sprockets 5" which are coupled to a common drive motor in a conventional manner, other guide sprockets 5" being idlers. No rollers 1 have been shown on the conveyor 5 in FIG. 2 for the sake of clarity.

A tank 8 at the first processing station normally contains water and a small amount of surfactant for cleaning the rollers l of dust, adhering loose fins, and other plastic scrap originating from the molding operation and subsequent mechanical finishing. The scrap particles drop to the bottom of the tank 8 and are removed from time to time.

The rollers 1, after being cleaned by immersion in the tank 8. pass between rapidly moving endless drive belts 9 as they enter a drying tunnel 10. The belts 9 are arranged in two pairs, and each pair tangentially engages therebetween a shell 4,4 to cause rapid rotation of the roller 1 fastened between the shells about the common axis of the shells and of the roller, the speed of rotation being sufficient to discharge most of the liquid in an ascending branch of the tunnel 10 by centrifugal forces so that the liquid flows back into the tank 8. The remaining adhering liquid is evaporated in the tunnel 10 in a stream of hot air admitted to the tunnel through a port 10' for flow countercurrent to the conveyor movement.

The dried rollers l are carried by the conveyor 5 into a tank 11 for partial immersion in a viscous, liquid adhesive composition. Upon leaving the tank 11, the rollers are rotated by driven belts 12 as described above with reference to the belts 9, but at a lower speed which permits the adhesive composition to be distributed uniformly over the roller surfaces.

The rollers thereafter enter a horizontal portion of the conveyor path between two vertically spaced electrodes 13,I4 extending in respective horizontal planes. At least the electrode 13 is perforated to permit staple fibers to be blown upward from a container 15 into the electrostatic field which is being maintained between the electrodes 13,14 in a conventional manner by means of a high-voltage, low-amperage source of direct current, not shown. The stream of staple fibers is largely retained on the passing rollers by the adhesive coating. A stationary rail 22 on the machine frame engages each shell 4,4 to rotate the roller 1 while it is being flocked in the electrostatic field, the length of the rail being such that the roller 1 makes one or two full revolutions.

The conveyor 5 thereafter carries the flocked rollers 1 into the bottom of an oven 16. Guide sprockets lead the conveyor back and forth in a horizontal direction and gradually upward against a descending stream of air blown into the oven 16 through an inlet 23 in the top wall of the oven and past electric heating elements 17 which raise the initial air temperature to about 150C. The air is discharged through multiple outlets 24 in the oven bottom.

The adhesive composition contains some solvent which is driven off first in the oven 16 and a heat-curing adhesive which is heated beyond its curing temperature and thereby set during the dwell time of typically 5 to minutes in the oven 16. Most of the fiber layer formed in the electrostatic flocking station is firmly bonded to the plastic roller as the latter leaves the hottest portion of the oven 16 near its top and passes through a cooling tunnel 18 into which ambient air is drawn.

The cooled rollers again pass between pairs of drive belts 19 which engage the shells 4,4 while the associated rollers move over Stationary brushes obscured in the view of FIG. 1 by the belts 19. The brushes remove loose and loosely adhering fibers from the flocked coating, and the loose fibers are removed through an exhaust hood 21 whose non-illustrated blower also is effective in drawing cold ambient air into the tunnel 18.

The rollers 1, which are now ready for use, enter an unloading station at which they are removed from the conveyor by operators, whereupon the empty conveyor continues to the loading station to complete its cycle of movement.

If the rollers 1 are badly contaminated when attached to the conveyor, drive belts and brushes may be arranged in the tank 8 as described with reference to the belts l9, and more than one tank may be employed for rinsing a detergent solution from the rollers.

To apply an adhesive composition to the cleaned rollers l by immersion has been found simple and practical, but other methods and suitable devices are well known in this art and may be resorted to. The use of coating rollers or spray applicators is specifically contemplated, and the coatings produced by such modified methods benefit by the turning motion imparted to the rollers by the drive belts 12.

Electrostatic flocking equipment which is now commercially available is readily modified for the purposes of this invention. It has been found that an arrangement in which the individual fibers flow in the electrostatic field against the force of gravity produces a particularly dense and uniform fiber coating as the fibers impinge on the horizontally moving roller 1 in a radial direction, at right angles to the outer cylindrical surface of the roller. Both natural and synthetic fibers have been employed successfully, and rayon fibers of deniers about 0.5 mm long are merely representative of a wide variety of fibers which have been employed successfully.

The fibers need not enter the electrostatic field on a stream of carrier air. Other arrangements are known and have been described, for example, in US. Pat. No. 3,496,91 1.

A countercurrent stream of hot air has been found to offer distinct advanta es for curing the adhesive over other methods of hea mg. The temperature difference between the travelling material and the air stream is practically constant in the oven 16 during continuous operation, and is thought to have a bearing on the observed favorable results.

The relatively fragile rollers are untouched by human hands from the loading station at the conveyor 7 to the unloading station 20, and this fact has been found to reduce scrap losses significantly. Other generally cylindrical bodies of fragile material may be processed in the conveyor shown in FIG. 2 without requiring any changes or with minor changes in the engaging elements of the device shown in FIG. 1 for fastening the bodies to be flocked to the conveyor chains 5,5 which act as carriers. Cylinders of very thin cardboard have been flocked successfully without distortion in the illustrated apparatus, and a desired pattern in the flocked surface was produced by suitably perforated templates arranged in the electrostatic field between the electrode 13 and the moving cylinders.

Obviously, many other modifications and variations of the present invention are possible in the light of the above teachings. It is therefore to be understood that, within the scope of the appended claims, the invention may be practiced otherwise than as specifically described.

What is claimed is:

1. In an apparatus for flocking fragile bodies having a substantially cylindrical, tubular shape about an axis, the apparatus including a continuous, elongated conveyor mounted for longitudinal movement in a closed loop, a plurality of fastening means longitudinally offset on said conveyor for fastening respective ones of said bodies to said conveyor, a plurality of processing means arranged along said conveyor and constituting stations for processing said bodies while said bodies are fastened to the moving conveyor, and rotating means at least at one of said stations for rotating said bodies about the respective axes thereof while moving through said one station and being processed therein, said conveyor including two endless carrier members elongated in a common direction and spaced from each other transversely of said direction, the improvement in each of said fastening means which comprises:

a. a bearing on each carrier member;

b. two engaging members respectively mounted on said bearing for rotation about a common axis transverse to said common direction; and

c. means for holding said engaging members simultaneously and coaxially engaged with one of said bodies while said one body extends between said engaging members.

2. Apparatus as set forth in claim 1, wherein said engaging members are spherical.

3. Apparatus as set forth in claim 1, wherein one of said bearings of each fastening means includes an outer face portion having a circular cross section and secured to the associated engaging member for joint rotation about said axis, said rotating means including a drive member mounted at said one station for tangential engagement with said outer face portion and for thereby rotating said associated engaging member. 

2. Apparatus as set forth in claim 1, wherein said engaging members are spherical.
 3. Apparatus as set forth in claim 1, wherein one of said bearings of each fastening means includes an outer face portion having a circular cross section and secured to the associated engaging member for joint rotation about said axis, said rotating means including a drive member mounted at said one station for tangential engagement with said outer face portion and for thereby rotating said associated engaging member. 